Impact of Targeted Neonatal Echocardiography on Patent Ductus Arteriosus Management in a Canadian Tertiary Care Neonatal Unit: A Retrospective Cohort Study

OBJECTIVE

 Comprehensive assessment of hemodynamic significance of a patent ductus arteriosus (PDA) is a common indication to perform targeted neonatal echocardiography (TNE). Impact of implementation of such an assessment on PDA management decisions remains to be reported. The objective of this study is to compare PDA-related hemodynamic information and PDA treatment decisions before and after introduction of TNE service.

STUDY DESIGN

 This was a retrospective cohort study at a tertiary level neonatal intensive care unit in Southwestern Ontario. We investigated two time periods: Epoch-1 (non-TNE 2013-2016) versus Epoch-2 (TNE 2018-2021). We included neonates < 32 weeks with PDA. Data on baseline clinical characteristics, PDA-related echocardiographic parameters, PDA treatment details, and relevant long-term outcomes were collected. Primary outcome was defined as PDA treatment rates and need for multiple courses. Secondary outcomes included availability of PDA hemodynamic data and neonatal mortality/morbidity (PDA-related) RESULTS:  A total of 275 neonates were included. A total of 162 were assessed by conventional echocardiography in Epoch-1, whereas 113 were assessed by TNE in Epoch-2. Baseline clinical characteristics were similar. Epoch-2 had more echocardiographic assessments per patient of 2.7 (±1.8) versus 1.9 (± 1.3), p < 0.001 in Epoch1. The mean postnatal age at first echocardiographic assessment was higher in Epoch-2 (12.7 days [ ± 14.6]) than in Epoch-1 (7.9 days [ ± 10.4]), p < 0.001. Comprehensive hemodynamic assessment of PDA-related echocardiographic parameters such as PDA size, shunt pattern, effect on systemic circulation, and pulmonary circulation were higher in Epoch-2. Overall, PDA treatment rates were comparable in the two time periods. The use of multiple courses of treatment was higher in Epoch-1 than in Epoch-2 (47.8 vs. 31.7%, p = 0.047). In Epoch-1, neonates received PDA treatment earlier than in Epoch-2.

CONCLUSION

 With the implementation of the TNE service, increased echocardiographic evaluations per patient were completed with availability of more comprehensive hemodynamic information about PDA. PDA treatment rates were similar in the two epochs, but need for multiple courses were less in TNE era.

KEY POINTS

· TNE allows comprehensive hemodynamic assessment of PDA.. · Implementation of dedicated TNE service led to increased use of echocardiography to assess PDA.. · Standardized hemodynamic assessment of PDA may allow improved individualization of treatment need..

Fluid and electrolyte management in preterm infants with patent ductus arteriosus

Optimal fluid management of preterm babies with suspected or confirmed diagnosis of patent ductus arteriosus (PDA) is frequently challenging for neonatal care physician because of paucity of clinical trials. There is wide variation in practice across neonatal units, resulting in significant impact on outcomes in Extremely Low Birth Weight (ELBW) babies with hemodynamically significant PDA. A delicate balance is required in fluid management to reduce mortality and morbidity in this population. The purpose of this review is to lay out the current understanding about fluid and electrolyte management in ELBW babies with hemodynamically significant PDA and highlight areas for future research.

Multimodal Assessment of Systemic Blood Flow in Infants

The assessment of systemic blood flow is a complex and comprehensive process with clinical, laboratory, and technological components. Despite recent advancements in technology, there is no perfect bedside tool to quantify systemic blood flow in infants that can be used for clinical decision making. Each option has its own merits and limitations, and evidence on the reliability of these physiology-based assessment processes is evolving. This article provides an extensive review of the interpretation and limitations of methods to assess systemic blood flow in infants, highlighting the importance of a comprehensive and multimodal approach in this population.

Pulmonary artery dopplers for early prediction of risk for bronchopulmonary dysplasia in extremely low birth weight babies

OBJECTIVE

The early abnormal pulmonary vasoreactivity observed in babies at risk of Bronchopulmonary dysplasia (BPD) increases the pulmonary vascular resistance. This can be assessed non-invasively using Time to Peak Velocity:Right Ventricular Ejection Time ratio (TPV:RVET) measured from pulmonary artery Doppler waveform obtained using echocardiogram. We postulate that screening for this early can predict BPD in this cohort. The objective of the study was to determine the utility of TPV:RVET in early prediction of BPD in Extremely Low Birth Weight (ELBW) babies born less than 1250grams Birth Weight.

METHODS

This was a single-center retrospective cohort study of ELBW babies born<29 weeks over 4 year period who had echocardiogram between 7-21 days of life. TPV:RVET ratio was measured from pulmonary artery Doppler waveform obtained using echocardiogram. The main outcome was BPD at 36 weeks corrected gestation. The predictive ability of TPV:RVET (cut off 0.34) for subsequent development of BPD was analyzed using ROC.

RESULTS

Of 589 ELBW<29 weeks, 207 babies were eligible. BPD was found in 60.4%. The TPV:RVET at 0.34 had sensitivity 76.8% (95%CI 68.4-83.9), specificity 85.4% (95%CI 75.8-92.2), positive predictive value 88.9% (95%CI 81.4-94.1), negative predictive value 70.7% (95%CI 60.7-79), and ROC area 0.811 (95%CI 0.757-0.864). Odds ratio of having BPD for TPV:RVET at 0.34 was 19.9 (95%CI 8.19-48.34) and increased by 1.07 (95%CI 1.05-1.09) with every additional days of mechanical ventilation. TPV:RVET ratio had 92.75% inter-observer agreement with kappa 0.83.

CONCLUSION

TPV:RVET ratio is a good and reliable early screening tool for subsequent development of BPD in ELBW babies with substantial inter-observer agreement.

30 Risk Factors for Stage III Necrotizing Enterocolitis in Very Low Birth Weight Neonates – A retrospective case-control study

Primary Subject area

Neonatal-Perinatal Medicine

Background

Stage III necrotizing enterocolitis (NEC-III) is a serious intestinal inflammatory disease in neonates, with high case fatality rate and significant morbidities including need for surgical intervention. Research focusing on risk factors for the development of NEC-III are lacking.

Objectives

To determine the risk factors for NEC-III and its outcomes among neonates born under 33 weeks gestational age (GA).

Design/Methods

This was a single-centre retrospective case-control study of preterm neonates born under 33 weeks GA who were admitted to Stollery Children’s Hospital neonatal intensive care unit (NICU), Edmonton, Alberta, between January 2015 and December 2018. NEC-III cases were compared with Stage II NEC (NEC-II) and matched with 2-4 non-NEC controls by GA ± 1 week and date of birth within 3 months. Univariate and multivariate analysis compared the risk factors for NEC-III, adjusting for GA, birth weight, and sex.

Results

Out of 1360 babies born &lt;33weeks, 71(5.2%) had NEC-II and above during the study period (Figure 1). NEC-III constituted 46% of the total number of NEC cases. Average age of onset of NEC-III was 13.7 days versus 23.9 days for NEC-II (p=0.01). Neonates with NEC-III were of lower GA (25.4weeks) compared to NEC-II(27.3 weeks) and non-NEC (26 weeks), (p=0.0008), had higher severity of illness with Score for Neonatal Acute Physiology Perinatal Extension-II (SNAPPE-II score) of 47.5 versus 28.4 for NEC-II and 37 for non-NEC ( p=0.003), spent more days on vasoactive agents (3.7 days versus 1.1 days and 1.8 days for NEC-II and non-NEC respectively; p=0.05).

There was a trend towards lower Apgar score &lt;7 at 10 mintues in NEC-III versus non-NEC (AOR 2.59, 95% CI [0.88-7.67]; p=0.085). Death or short bowel syndrome was higher for NEC III (AOR 12.4, 95% CI [1.16-132.28]; p=0.037).

Conclusion

In this case-control study of neonates born under 33 weeks GA, after adjustment for known confounders, duration of UAC and prolonged rupture of membranes were significantly associated with increased incidence of NEC-III. Composite outcome of mortality or short bowel syndrome were higher in NEC-III.

43 Pulmonary Artery dopplers for early prediction of Bronchopulmonary Dysplasia (BPD) in Extremely Low Birth Weight babies (ELBW): A forgotten tale

Introduction/Background

BPD is a chronic lung disease that affects ELBW babies and contributes significantly to their morbidity and mortality. The early abnormal vasoreactivity observed in babies at risk of BPD increases the pulmonary vascular resistance and can be assessed non-invasively using Time to Peak Velocity: Right Ventricular Ejection Time ratio (TPV: RVET) that is calculated from pulmonary artery doppler waveform. We postulate that screening for this condition early may be useful to predict BPD in this cohort, which may provide prognostic information as well as early clinical management of the ELBW at risk of developing BPD and therefore can potentially present a window of opportunity for therapeutic intervention.

Objectives

1. To determine utility of TPV/RVET ratio in predicting the risk for BPD in ELBW babies in a tertiary center.

2. To determine utility of TPV/RVET(c) ratio in predicting the risk for BPD in ELBW babies in a tertiary center.

Design/Methods

This is a retrospective cohort study of ELBW babies &lt;29 weeks admitted to the Neonatal Intensive Care Unit at Stollery Children Hospital (SCH) over a 4 year time period and had early echocardiograms performed between 7-21 days of life. These babies were further identified to have BPD or no BPD at 36 weeks CGA. TPV/RVET ratios were measured by two reviewers from pulmonary artery doppler waveforms and were corrected for heart rate. The predictive ability of TPV/RVET and TPV/RVET(c) for subsequent development of BPD were analyzed using ROC curve. Inter observer agreement was evaluated. Logistic regression analysis was performed to derive a model that can be used in the 2nd to 3rd weeks of life, to predict the subsequent development of BPD at 36 weeks CGA. Infants with congenital heart disease (other than PDA, persistent foramen ovale/atrial septal defect and Ventricular Septal Defects), congenital lung malformations, multiple congenital anomalies and chromosomal anomalies were excluded.

Results

Out of 589 ELBW babies &lt;29 weeks admitted to SCH NICU, 207 infants were eligible with early echocardiograms done at a mean age of 12.6 days (SD 4.1). One-hundred-and-twenty-five babies (60.4%) were found to have BPD. Babies with BPD were of lower gestational age (25.6 Vs 26.4, p-0.0001), sicker at birth (SNAPPE II 42.3 Vs 33.2, p-0.0024), had higher incidence of PDA needing surgical ligation (18.4% Vs 4.9%, p-0.005) and had spent more days on mechanical ventilation (39.8 Vs 12.5, p&lt;0.0001) than those without BPD. Both TPV, TPV/RVET and its corrected ratios were significantly lower in ELBW babies with BPD compared to non-BPD babies (p&lt;0.0001). The TPV/RVET ratio (cut off 0.34) and TPV/RVET(c) (cut off 0.54) had Sensitivities [76.8% (95%CI 68.4-83.9) and 72% (95%CI 63.3-79.7)], Specificities [85.4% (95%CI 75.8- 92.2) and 84.1% (95%CI 74.4-91.3)], Positive Predictive Values [88.9% (95%CI 81.4-94.1) and 87.4% (95%CI 79.4-93.1)], Negative Predictive values [70.7% (95%CI 60.7- 79) and 66.3% (95%CI 56.4-75.3)] and ROC area [0.811 (95% CI 0.757-0.864) and 0.781 (95% CI 0.725-0.837)] respectively. Multi variant logistic regression analysis showed Odds Ratio(OR) for having BPD at TPV/RVET cut off 0.34 and TPV/RVET(c) cut off 0.54 to be 19.9(95%CI 8.19-48.34) and 16.3(95% 6.78-39.33) respectively and the OR increased by 1.07(95%CI 1.05-1.09) and 1.08(95% CI 1.05-1.10) with every additional days of mechanical ventilation respectively. TPV/RVET ratio had 92.75% inter-observer agreement with kappa 0.83.

Conclusion

TPV/RVET and its corrected ratio are good and reliable early screening tools for subsequent development of BPD in ELBW babies with substantial inter-observer agreement.

Two variable model namely TPV/RVET&lt;0.34 and mechanical ventilation or TPV/RVET(c) &lt;0.54 and mechanical ventilation can be used in the 2nd to 3rd week of life to predict subsequent development of BPD at 36 weeks CGA in ELBW babies.

Intraspecific variations in Cyt b and D-loop sequences of Testudine species, Lissemys punctata from south Karnataka

The freshwater Testudine species have gained importance in recent years, as most of their population is threatened due to exploitation for delicacy and pet trade. In this regard, Lissemys punctata, a freshwater terrapin, predominantly distributed in Asian countries has gained its significance for the study. A pilot study report on mitochondrial markers (Cyt b and D-loop) conducted on L. punctata species from southern Karnataka, India was presented in this investigation. A complete region spanning 1.14 kb and ∼1 kb was amplified by HotStart PCR and sequenced by Sanger sequencing. The Cyt b sequence revealed 85 substitution sites, no indels and 17 parsimony informative sites, whereas D-loop showed 189 variable sites, 51 parsimony informative sites with 5′ functional domains TAS, CSB-F, CSBs (1, 2, 3) preceding tandem repeat at 3′ end. Current data highlights the intraspecific variations in these target regions and variations validated using suitable evolutionary models points out that the overall point mutations observed in the region are transitions leading to no structural and functional alterations. The mitochondrial data generated uncover the genetic diversity within species and conservationist can utilize the data to estimate the effective population size or for forensic identification of animal or its seizures during unlawful trade activities.

Mevalonate-metabolizing enzymes in Arachis hypogaea

The activities of the mevalonate metabolizing enzymes-HMG-CoA reductase, mevalonate kinase, mevalonate phosphokinase and mevalonate pyrophosphate decarboxylase -were assayed with the respective substrates in green seedlings of Arachis hypogaea. MVAPP decarboxylase is the rate-limiting step among these enzymes and is inhibited by phenolic acids. Its activity in the seedlings was found to decrease in the absence of light and on treatment with abscisic acid. These results suggest that regulation of isoprene pathway in groundnut seedlings may occur at the level of mevalonate decarboxylation.

Effect of flickering light stress on certain biochemical parameters in rats

The acute effects of flickering light of 80 Lux intensity for thirty minutes duration, on plasma corticosterone, total serum cholesterol, serum triglycerides, serum glutamic pyruvic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT) levels were studied in albino rats. Statistically significant increase was observed in the corticosterone, cholesterol, SGOT and SGPT, while a marked reduction was seen in the serum triglyceride level, indicating that the flickering light is a potent stressor to these animals causing alterations in the biochemical parameters studied.